Last week ConservativeHome caused a political furore by urging David Cameron to drop the NHS Bill, arguing that it does little to genuinely reform the health service but would damage the government's reputation and thereby weaken its ability to fight successfully for genuinely radical causes.

As a consequence, there was only a tiny bit of attention on the merits of the bill but intense focus on the internal forces lined up against each other. It therefore became necessary for the Prime Minister's office to reassert vigorously that he was determined to face down the critics and stick with his policy (even though Downing Street had apparently briefed against it a few days before.) This brings two points to mind:

1) It seems of overriding importance to political leaders to show that they cannot be made to change their minds in response to criticism, as this might make them appear weak. Much more than other species, politicians feel heavily invested in their earlier decisions, even when those decisions were the result of uncomfortable compromises. When politicians do change their minds (which happens very frequently) they invariably strive to show that they haven't actually done so. But why? I can think of no occasion when a leader bowing to public opinion thereby appeared weak to that public. Quite the opposite, voters tend to like it when leaders change their minds to agreement with them, seeing it as a reassuring sign of reasonableness. (We mainly admire conviction when it accords with our own conviction; mostly, we do not admire Bob Crow, for example).

If the Bill does end up proving too unpopular (I don't say it will: like most people, I haven't a clue whether it is in fact an excellent and highly necessary reform package or a heap of minor measures), the government can always decide to ditch it and can even turn that moment into a pro-NHS triumph ("we have listened to doctors and nurses", etc).

2) The principal method we have of deciding whether a course of action is a good one or a bad one is by seeing who is ranged in favour and who is against. That was abundantly clear in the past few days. Even among political activists, few can argue convincingly for or against the changes the Bill would make; actually, few could even list any two of them. They could tell you much more about who stands for and against.

Whatever we pretend to ourselves, we do not really weigh up the merits but the opinions. It's how we naturally think. I've argued this rather a lot previously in this space, and usually am criticised in the comments section for downgrading conviction. In fact I do not disrespect analysis or conviction, quite the opposite; I just observe that when trying to predict what will happen next, one shouldn't count on it. And I can't help pointing out that Tim Montgomerie himself, though the epitome both of the cool analyst and the conviction activist, was himself not arguing about the actual value of the bill but – purely pragmatically – about the best tactical use of limited political capital. We all agree really.